Supplemental device for attachment to an injection device

Abstract

A supplemental device for attachment to an injection device including a dosage window covering a sleeve on which dose values are marked is disclosed. The supplemental device comprises a main body; an arrangement for supporting the main body of the supplemental device in a predetermined positional relationship with the injection device; a transparent protection window located at a surface of the main body that is aligned with the dosage window of the injection pen when in use; a sensor arrangement supported in the main body and having a sensor directed at the protection window; an illumination arrangement comprising one or more sources of light, each of the one or more sources of light being directed at the protection window; and a dispersing part, which may be diffusing or scattering, located on an optical path between a first one of the one or more sources of light.

The invention claimed is: 
     
       1. A supplemental device configured for attachment to an injection device including a dosage window covering a sleeve on which dose values are marked, the supplemental device comprising:
 a main body; 
 an arrangement for supporting the main body of the supplemental device in a predetermined positional relationship with the injection device; 
 a transparent protection window located at a surface of the main body that is configured to be aligned with a dosage window of the injection device when in use; 
 a sensor arrangement supported in the main body and having a sensor directed at the protection window; 
 an illumination arrangement comprising one or more sources of light, each of the one or more sources of light being directed at the protection window; and 
 a light dispersing part located on a surface of the protection window and on an optical path between a first one of the one or more sources of light and a point on the dosage window at which reflection to the sensor would occur. 
 
     
     
       2. A supplemental device as claimed in  claim 1 , wherein the protection window has an optical power. 
     
     
       3. A supplemental device as claimed in  claim 1 , wherein the protection window is sealed to the main body so as to prevent the ingress of material into the supplemental device around the protection window. 
     
     
       4. A supplemental device as claimed in  claim 1 , wherein the light dispersing part is provided on a surface of the protection window that is closest to the sensor arrangement. 
     
     
       5. A supplemental device as claimed in  claim 1 , wherein the light dispersing part comprises plural prisms. 
     
     
       6. A supplemental device as claimed in  claim 1 , wherein the light dispersing part comprises a scattering or diffusing part. 
     
     
       7. A supplemental device as claimed in  claim 1 , wherein the light dispersing part comprises a roughened surface of the protection window. 
     
     
       8. A supplemental device as claimed in  claim 1 , wherein the light dispersing part is integral with the protection window. 
     
     
       9. A supplemental device as claimed in  claim 1 , wherein the light dispersing part is attached to the surface of the protection window. 
     
     
       10. A supplemental device as claimed in  claim 1 , wherein the light dispersing part is located on an optical path between a first one of the one or more sources of light and a point on a surface of the dosage window that is furthest from the sensor arrangement, the point being a point at which reflection to the sensor arrangement would occur. 
     
     
       11. A supplemental device as claimed in  claim 1 , wherein the light dispersing part is located on an optical path between a first one of the one or more sources of light and a point on a surface of the dosage window that is closest to the sensor arrangement, the point being a point at which reflection to the sensor would occur. 
     
     
       12. A supplemental device as claimed in  claim 1 , wherein the illumination arrangement comprises plural sources of light. 
     
     
       13. A supplemental device as claimed in  claim 12 , wherein the plural sources of light are located at different positions around the sensor arrangement. 
     
     
       14. A system comprising a supplemental device as claimed in  claim 1  and an injection device. 
     
     
       15. A system as claimed in  claim 14 , wherein a surface of the protection window that is furthest from the sensor arrangement lies on a curved surface of an imaginary cylinder having an axis coincident with a longitudinal axis of the injection device and wherein the surface of the protection window that is furthest from the sensor arrangement lies in close proximity with a dosage window of the injection device when the supplemental device is installed on the injection device.